1. Field of Invention
The present disclosure relates generally to a method of characterizing a target using ellipsometry. More specifically, the present disclosure relates to illuminating a target beams of light with more than one moveable objects, recording reflections from the target, and identifying target characteristics based on the recorded reflections. Yet more specifically, the present disclosure relates to illuminating a target with two separately directed beams of linearly polarized light projected from two disparate airborne platforms at orthogonal polarization orientations, recording polarized reflections from the target, and identifying target characteristics based on the recorded reflections and polarization analysis.
2. Description of Prior Art
Reconnaissance, target location, and target identification, are necessities when engaged in combat and other military operations. One aspect of reconnaissance, combat related or not, includes identification and/or monitoring of certain targets. Examples of reconnoitered targets include weapons based vehicles, such as fighter and/or bomber aircraft (fixed wing as well as rotary), tanks, battleships, missiles, and the like. Transport vehicles can also be tracked as targets, such as personnel carriers (armored or not), trucks, jeeps, cargo aircraft, transport aircraft, ships, and the like. The advent of an increasingly mechanized and technology laden battlefield has increased movement on and to the battlefield, thus increasing the requirements for faster, more responsive, and more accurate and discriminating reconnaissance.
Currently, targets can be directly imaged using broadband visible light, short, mid, or long wavelength infrared, as well as near-monochromatic laser light. Hyperspectral sensors can be employed to provide a spectral signature and/or target imagery, with a limited degree of spectral/spatial resolution. The target image may yield its shape, aspect ratio, orientation, range, polarization behavior, and time resolved vibration signatures. Target surface properties of texture and/or color may be assessed using a land based laser radar, but at highly degraded resolution compared to optical systems.